The 1940 Winter Olympics, which would have been officially known as the V Olympic Winter Games, were to be celebrated in 1940 in Sapporo, Japan, but the games were eventually canceled due to the onset of World War II.

Sapporo was selected to be the host of the fifth edition Winter Olympics scheduled February 3-12, 1940, but Japan gave the Games back to the IOC in July 1938, after the outbreak of the Second Sino-Japanese War in 1937. Sapporo subsequently hosted the 1972 Winter Olympics.

The IOC then decided to give the Winter Olympics to St Moritz, Switzerland, which had hosted in 1928. Due to controversies between the Swiss organizing team and the IOC, the Games were withdrawn again.

In the spring of 1939, the IOC gave the 1940 Winter Olympics, now scheduled for February 2-11, to Garmisch-Partenkirchen, Germany, where the previous 1936 games had been held. Three months later Germany invaded Poland on September 1 to ignite World War II, and the Winter Games were cancelled in November. Likewise, the 1944 games, awarded in 1939 to Cortina d'Ampezzo, Italy, were cancelled in 1941. St Moritz held the first post-war games in 1948, while Cortina d'Ampezzo hosted in 1956.